/in/foo.cc: In function 'std::string multiply_string(std::string, int)':
/in/foo.cc:44:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     while (start < res.length() - 1 && res[start] == '0') start++;
      |            ~~~~~~^~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'std::string sub_one(std::string)':
/in/foo.cc:58:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |     while (start < s.length() - 1 && s[start] == '0') start++;
      |            ~~~~~~^~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void solve()':
/in/foo.cc:131:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  131 |     for (int i = 1; i < A.length(); i++) {
      |                     ~~^~~~~~~~~~~~
/in/foo.cc:138:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  138 |         for (int L = 1; L <= P2.length(); L++) {
      |                         ~~^~~~~~~~~~~~~~
/in/foo.cc:169:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  169 |         if (offset < 0 || offset > X.length()) continue;
      |                           ~~~~~~~^~~~~~~~~~~~